Difference between revisions of "Developer Area/Significant Bug Documentation"

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(Created page with "= Security bugs = Take care when trying to "fix" the oddities that remedies for these bugs have caused. [https://bugs.launchpad.net/mahara/+bug/1047111 #1047111] <tt> There is…")
 
(Security bugs)
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Take care when trying to "fix" the oddities that remedies for these bugs have caused.
 
Take care when trying to "fix" the oddities that remedies for these bugs have caused.
  
[https://bugs.launchpad.net/mahara/+bug/1047111 #1047111]
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[https://bugs.launchpad.net/mahara/+bug/1047111 #1047111] XML External Entity parsing.
  
<tt>
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There is a security issue with the default XML parser for PHP, where ENTITY fields areloaded and substituted in text parts. <br/><br/>
There is a security issue with the default XML parser for PHP, where ENTITY fields are
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This allows possible attackers to read from internal networks, or files readable by the web server user.<br/><br/>
loaded and substituted in text parts.  
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This includes reading of the config.php file, which contains sensitive information such as the database password, and the password salt field.<br/><br/>
 
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The fix for this was to include a call to libxml_disable_entity_loader(true) during the initialization of a page. This is based on a report from Mike Haworth<br/><br/>
This allows possible attackers to read from internal networks, or files readable by the
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The vulnerability was present in the admin area when uploading Leap2A users, and also in the user page area where a user could provide a RSS feed with specific XML ENTITY fields.<br/><br/>
web server user.
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More information can be found at the following:
 
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  http://projects.webappsec.org/w/page/13247003/XML%20External%20Entities
This includes reading of the config.php file, which contains sensitive information such
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  http://websec.io/2012/08/27/Preventing-XEE-in-PHP.html<br/><br/>
as the database password, and the password salt field.
+
This affects only php 5.2.11 and upwards, and likewise the fix must check for the libxml_disable_entity_loader function before doing it's thing.
 
 
The fix for this was to include a call to libxml_disable_entity_loader(true) during the
 
initialization of a page. This is based on a report from Mike Haworth
 
 
 
The vulnerability was present in the admin area when uploading Leap2A users, and also in
 
the user page area where a user could provide a RSS feed with specific XML ENTITY fields.
 
 
 
More information can be found at the following:
 
http://projects.webappsec.org/w/page/13247003/XML%20External%20Entities
 
http://websec.io/2012/08/27/Preventing-XEE-in-PHP.html
 
</tt>
 

Revision as of 14:26, 18 September 2012

Security bugs

Take care when trying to "fix" the oddities that remedies for these bugs have caused.

#1047111 XML External Entity parsing.

There is a security issue with the default XML parser for PHP, where ENTITY fields areloaded and substituted in text parts. 

This allows possible attackers to read from internal networks, or files readable by the web server user.

This includes reading of the config.php file, which contains sensitive information such as the database password, and the password salt field.

The fix for this was to include a call to libxml_disable_entity_loader(true) during the initialization of a page. This is based on a report from Mike Haworth

The vulnerability was present in the admin area when uploading Leap2A users, and also in the user page area where a user could provide a RSS feed with specific XML ENTITY fields.

More information can be found at the following: http://projects.webappsec.org/w/page/13247003/XML%20External%20Entities http://websec.io/2012/08/27/Preventing-XEE-in-PHP.html

This affects only php 5.2.11 and upwards, and likewise the fix must check for the libxml_disable_entity_loader function before doing it's thing.